New current-mode quadrature oscillators using CDTA

Abstract

This letter proposes two new realizations of current-mode (CM) quadrature oscillator (QO) using CDTA (Current Differencing Transconductance Amplifier) as the active element. The proposed circuits are canonic in component count and use two grounded capacitors which is ideal from IC fabrication point of view. Both the oscillator circuits provide current controllability of frequency of oscillation (FO) and the circuits enjoy the advantage of independent control of condition of oscillation (CO) and FO which makes them suitable as variable frequency oscillators (VFOs). B2SPICE simulation results are included that validate the working of the circuit. © IEICE 2009.